What this code means
B1140 may mean the power window master switch is seeing the driver’s window position differently than where the window actually is.
What the vehicle may do
- The driver’s power window may not operate as expected.
- Automatic window functions may be affected.
- The code may store even when the window still moves.
Possible fault areas
- Possible master switch reset or learned-position issue.
- Possible driver’s window position detection circuit concern.
- Possible power window master switch or door multiplex control involvement.
- Possible related network or power window code context.
Diagnostic path
Code overview
On this Honda CR-V, B1140 points to a driver’s power window position detect circuit problem. In plain terms, the power window master switch may think the driver’s glass is in one position when the actual window position is somewhere else. The customer may notice the driver’s window acting incorrectly during manual or automatic operation, or the system may simply store the code. The broad areas to keep in mind are the master switch reset or learned position, the driver’s window position detection side of the circuit, and any network or power window codes that may be affecting the diagnosis.
Start with the basic checks
Before getting into the specific B1140 routine, start with the basic system checks and follow a structured diagnostic approach. Don’t jump straight to parts. This code is about the master switch’s recognized window position not matching the actual driver’s window position, so the diagnosis needs to stay focused on that command-and-position relationship.
Handle other codes first
If other power window or B-CAN related codes are present, check what they mean first and handle that diagnostic path before continuing with B1140. When there are multiple codes, use the multiple-code network diagnosis path rather than treating B1140 by itself. That keeps you from chasing a position code that may be secondary to another system issue.
Reset the master switch
For the B1140 path, the specified work item is resetting the power window master switch. This fits the fault logic: if the switch’s learned or recognized driver window position is out of sync with the actual glass position, the reset is the required service step before confirmation.
Confirm the operation
After the reset, turn the vehicle to the ON mode. Then use the power window master switch to manually open and close the driver’s power window. Keep this confirmation separate from the reset step: the reset is the service action, and this manual window movement is how you confirm the system can track the driver’s window position correctly afterward.
Wrap-up
The key point with B1140 is to verify the master switch and driver’s window position agree again before calling the job done. If the earlier diagnostic path doesn’t line up, pause, recheck the basics and the other-code path, and avoid guessing. For more diagnostic training, visit stepdiagnostics.com.
Final check
B1140 is often a position-recognition problem, so the diagnostic logic is to handle related code context first, reset the master switch, then confirm driver’s window movement in ON mode.
For more guided automotive diagnostics, visit STEP Diagnostics.
